Known gaskets of the above type are comprised essentially of a portion in the form of a clothes-pin shaped channel or U to be engaged by pinching or pressing onto the edge of the panel, and a portion fixed to or integral with the U or channel for performing the seal function.
In this kind of gasket or seal strip, the portion in the form of the channel or U is interiorly provided with one or more lips projecting toward the inside of the U and which elastically bear on a wall of the panel in a manner to exert pressure and obtain the necessary sealing.
To facilitate mounting the seal strip, it is agreed that the channel or U shaped portion should be able to be engaged onto the edge of the panel with minimal effort, and should have great resistance to removal from the panel. However, if the actually known seals have a good resistance to removal, they have unfortunately, a high resistance to engagement on the edge of the panel, which is a disadvantage shown for example by the deterioration of the lips.
In addition, the panel on which the portion of channel or U shape is mounted can have variable thickness. It follows, as a consequence that the same channel should have the same ease of engagement and the same high resistance to removal for panels of different thickness, or for a panel having portions of different thickness, which is not the case with the prior known seal strips or gaskets.